1. Field of the Invention
The present invention relates to a technique for enhancing the realism of sound in movie theaters and home theaters.
2. Description of the Related Art
The multichannel surround technology is one audio technology that is widely employed in audio equipment used in movie theaters and home theaters. The multichannel surround technology is a technology which provides a listener(s) with highly realistic sound by controlling a sound image of sound that is reproduced together with an image of a video content using plural speakers that are disposed in front of and on the right and left of the listener(s). The ITU (International Telecommunication Union) issued recommendations relating to the arrangement positions of speakers in the multichannel surround technology. For example, in a 5-channel surround technique, a center-channel speaker is disposed in front of a viewer(s) (i.e., on the side where a screen is provided) and front-left and front-right speakers are disposed on the left and right of the center-channel speaker, respectively. Furthermore, a left surround speaker and a right surround speaker are disposed on the left and right of the viewer(s), respectively. Among these five speakers, the center-channel speaker is used for reproduction of sound to be localized in front of the viewer(s), such as speeches. The front-left and front-right speakers are used for sound image localization on the front-left of, in front of, or on the front-right of the viewer(s). The left surround speaker and the right surround speaker are used for reproduction of sound to be localized on the left or right of or behind the listener(s).
Incidentally, among video contents to show at movie theaters and home theaters are ones in which each frame reproduction image was subjected to processing for 3D vision. Such 3D video contents include many scenes that were taken so that viewers would feel as if persons appearing were located on the viewer(s)' side of the screen. In such scenes, the realism of sound could be enhanced further while a video content is showing if a viewer who hears a speech of a person were allowed to feel as if its sound source were close to his or her ears. However, the conventional multisurround technology cannot control the distance of sound a viewer feels when hearing sound emitted from speakers. The present invention has been made in view of the above problem, and an object of the present invention is to make it possible to control the distance of sound a listener feels when hearing sound emitted from speakers.